Fabrication Of Double Metal Feram Without Degradation Of Remnant Polarization By Using Ir/Irox Capacitor Contact Barrier Layer

The capacitor contact barrier (CCB) structure was introduced to prevent both the Pt/Al reaction and the Ti effect to a SET capacitor. TiN CCB layer could not perfectly block the Pt/Al reaction. And ferroelectric properties of SET capacitor were degraded during back-end processes. So, we applied a new Ir/IrOx layer to the CCB layer. The SET capacitor with the Ir/IrOx CCB layer exhibited higher delta polarization (dP similar to 15 muC/cm(2)) after the metal-2 etching process, compared with the value in the case of the TiN CCB layer (dP similar to 12 muC/ cm(2)). Moreover, the dP uniformity was improved to 4% when we used the Ir/IrOx CCB layer, from the similar to 20% of the TiN CCB layer. And the defect formed by the Pt/Al reaction was not found in the Ir/IrOx CCB layer structure.